Uruguayan media reported that Nin Novoa said the Brazilian government tried to "buy" Uruguay's vote to prevent Caracas from leading the regional group that also includes Argentina and Paraguay.

"The Brazilian government received with a profound discontent and surprise the statement from Chancellor Nin Novoa," Brazil's foreign ministry said in a statement.

The leadership spat in the group has raised tensions and opened ideological fault lines in a region struggling with a drop in commodity prices and political turmoil.

Since Brazil's President Dilma Rousseff was suspended in May, her replacement Michel Temer has moved the country away from leftist allies such as Venezuela and toward traditional allies the United States and Europe.

Argentina and Paraguay, once close allies to Caracas, have also moved to undermine Venezuela as the country struggles with economic and political crises.

Rousseff and her predecessor Luiz Inacio Lula da Silva supported Venezuela's former President Hugo Chavez and his successor Nicolas Maduro, who took office when Chavez died in 2013.